Dry shaver



M. GRlVET-TO Dec. 22, 1942.

DRY .sHAvER Filed Aug. 29, "1939 MICHELE atented Dec.. 22, i 12 par snavel:

Michele Grlvetto, Turin,

, Propert Allen I; vta the Application Amst 29,1939, sesame. esta t rnmiy september a, `193s.

(cl. soi-'isi lClaims.

very rapid angular oscillations and a stationary blade obtained on or forming part of the cylindrical casing of the movable blade.

An object of this inventionis to provide a dry shaveriof the above-mentioned type, in which the stationary blade isv constituted by one side of a longitudinal substantially continuous slot in the cylindrical casing, which is further provided with a bearingA surface for the skin, the plane of said surface being substantially tangential to the arcA of circle describedY by the cutting edge of the movable blade and normal to the plane passing through the axis of oscillation of the movable blade and .the cutting edge of the stationary blade. With this arrangement the hair is cutiat its root, that is, quite near to the skin, without hurting the latter. v

A further object of the invention is to provide a dry shaver of the above-mentioned type,Y in

-which cuts normal to the cutting edge of the stationary blades are provided in the bearing surface for the skin on the side opposite to the stationary blade to form guides for the hair. y

Another object of the invention is to provide in a dry shaver of theabove-mentioned type narrow bridges arranged transversely to the slot and connecting the cutting edge of the stationary blade to the portion of the bearing plane opposite to said cutting edge. These bridges are adapted to stiffen the stationary blade and obtain a continuous bearing plane for the skin; they moreover show the advantage that the hair. is not bent between the bearing plane and the skin and is prevented from being brought between said parts, thus holding the cutting edge of the stationary blade at a distance from theskin; the hair is thus cut at its root.

These and'other advantages will appear from the following specication with reference to the annexed drawing, in which:

Figure 1 is a longitudinal. section of head;

Fig. 2 is a section on line II-Il of Fig. l;

Fig. 3 is a section on line YIII-III oi' Fig. l;

Fig. 4 is a partial section on line IV--IV of Fis. 2:

Fig. 5 is a front view of the movable blade;

Fig. 5a is a sectional view thereof lFig. 6 is a partial cross section of the shaver head showing a modified form;

Fig. 7 is a side partial view of Fig. 6 seen in the direction of the arrow VII;

the shaver Fig.l 8 is a view similar to Fig. 6 of a further modied construction, and

Fig. 9 is a partial side view` of Fig. 8 seen in the direction' of the arrow 1X.

Referring to Figures 1 to 5, l denotes the semicylindrical casing receiving the movable blade 2,

which oscillates about the geometrical axis li of the casing in the manner' described hereinafter. In. the cylindrical wall of the casing I is a milled cut t which extends over the whole length of the casing, except the regions in nearest proximity to its end portions. The bottom of the milled cut 3 forms a bearing surface 4 for the skin, on which the shaver is moved to and fro.

The bearing surface 4 is discontinuous owing to theslot i which forms the cutting edge 5 for the stationary blade. This cutting edge 5 is situated at the end of the radius 6 which is normal to the bearing surface 4. As the stationary blade is necessarily of-a certain thickness, its edge is tapered, in order to bring the cutting edge 5 as near as possibley the cutting edge of the movable blade oscillating underneath the former.

The blade 2 is provided on the axis of oscillation 0 with two semlcylindrical surfaces i I, seated in correspondingly shaped recesses in two pins ill. 'I'he latter are subjected-to the action of springs i3, that push the free blade end against the edges la oi the casing I, insuring a perfect articulation with a minimum friction for the blade oscillations.

The pins ill and springs i3 are eccentrically mounted in cylinders i2, rotatable in seatings formed in a supporting base I9 xedly connected with the casing I.

The cylinders i2 are formed with lower grooves i2a which permit angular displacements of the cylinders i2, thereby transversely displacing the pins i0, in order to adjust the support of the blade 2. The cylinders i2 are locked in their adjusted position by means of set screws it. The blade 2 is formed at its lower -end with a central projection I 5, having a slot IB receiving an eccentric pin il on va shaft i8. The shaft i@ is rotated by a'motor (not shown) suitably incorporated in the shaver, imparting to the blade 2 very rapid oscillatory movements.

The width of said oscillations is such that the cutting edge of the movable blade2i does not move over the whole width of the slot 1, but only over a part thereof. ln fact, the position of the blade 2, shown in Figure 2, approximately corresponds to the final blade position. The object of this arrangement is to facilitate admission of longer hair into the slot i and to set it upright for cutting. The grooves t (Figure 4) formed in the portion o the bearing surface opposite the cutting edge 5, exert a combing action on the longer hair, assisting in setting it upright in the proper direction as it enters the slot 'l'. In order to facilitate the passage of this long hair in the region situ- `ated between the blade 2 and cutting edge 5, the

blade 2 may also be provided with grooves 8 (Figure 5) which are, however, inclined in order to secure continuousness of the blade cut.

Referring to Figures 6 and 7:

The general construction corresponds to that shown in the formerly described construction, and details need not be repeated. The bearing surface @i for the skin still is normal to the radius 6 passing through the edge of the stationary blade 5. The modification concerns only the portion l of the casing opposite the stationary blade. This portion is formed with cuts 20 instead of simply with grooves as provided in the constructions shown in Figs. 1 to 5, and extends towards the stationary blade so that the width i the slot 2| is limited to about l5/m millimeter. The width of the extreme angular displacements of the oscillating blade 2 at its edge is greater and extends beyond the slot portions 2| at both sides thereof.

Figure 6 shows by way of example in dotted and full lines, respectively, the two final positions of the oscillating blade 2. It will be obvious that, in order to reach the position shown in full lines, `the oscillating blade moves over a certain length of the zone of the member I formed with cuts 2l The support i9 for the outer casing and cylinders l2 may be moulded from a plastic composition, for instance of the type known under the registered name of Bakelite, which makes construction less expensive.

In order to prevent out hair from entering the mechanism for driving and adjusting the movable blade, the semicylindrical chamber in which the blade 2 oscillates, is closed towards this mechanism by a plate 22 having only holes for the passage of the tail I actuating the blade 2 and pins IQ supporting said blade.

Referring to Figs. 8 and 9, the portion 23 of the bearing surface for the skin, 'opposite'to the cutting edge 2s of the stationary blade, is connected to the remaining part 25 of said bearing surface by means of a set of narrow bridges 2t formed by providing in the portion ib of the casing deep cuts 2l perpendicularly to the stationary blade. The width of said bridges is about 3/10 mm., while the cross cuts may be, for instance, of "/w-n/io mm. width.

In order to cut the hair to the root, as the slot 28 in the construction now described is no longer continuous, the cutting edge of the blade is tapered, as shown in the drawing, with a large development of the tapered surface. This taper is economically formed by the same milling cutter used to form the cuts 2i'. The milling cutter is shown in dotted lines in Figure 8, where it is denoted by the letter F. By e'ect of the blade taper, the skin slightly enters the cuts 21 by eifect of the pressure with which the shaver is applied to the skin, and brings the hair root against the movable blade 2, 'by which the hair is out as the movable blade cornes over the cutting edge 2d of the stationary blade.

The cuts 2 subdivide the hair. bringing it on the stationary blade, where they are cut by the movable blade, as stated above.

What I claim is:

l. A dry shaver comprising a semi-cylindrical casing, a blade mounted for oscillation in said cylindrical casing about the axis of the latter and having a tutting edge movable substantially along an arc of the inner cylindrical surface of said casing, the outer portion of the senil-cylinder being cut away between the ends thereof along a plane extending substantially tangentially to the inner cylindrical surface thereof to provide a cutting .edge at the` intersection of said plane and the inner cylindrical surface, said semi-cylinder being further out away to provide a slot having the cutting edge as one of its edges, and means for imparting to said oscillating blade an oscillatory motion extending over a part only of the slot width.

2. A dry shaver comprising a semi-cylindrical casing, and a blade mounted for oscillation in said cylindrical casing about the axis of the latter and having a cutting edge movable substantially along an arc of the inner cylindrical surface of said casing, the outer portion of the semi-cylinder being cut away between the ends thereof along a plane extending substantially tangentially to the inner cylindrical surface thereof at a. plurality of regions to provide a cutting edge at the intersection of said plane and the inner cylindrical surface, said semicylinder being further cut away to provide a plurality of slots extending from the cutting edge to receive hairs to be cut.

3. A dry shaver comprising a cylindrical casing, a blade in said casing mounted for oscillation about the axis of the latter, and a spring support in said casing for said blade tending to bring the cutting edge of said blade into engagement with the inner cylindrical surface of said casing, the outer portion of the semi-cylinder being cut away between the ends thereof along a plane extending substantially tangentially to the inner cylindrical surface thereof at a plurality of regions to provide a cutting edge at the intersection of said plane and the inner cylindrical surface, said semi-cylinder being further cut away to provide a plurality of slots extending from the cutting edge to receive hairs to be cut.

4. A dry .shaver as claimed in claim 3, in which the free end of the movable blade is provided with oblique grooves adapted to comb the longer hair to facilitate their admission into the cutting zone.

. 5. A dry shaver comprising a cylindrical casing, a blade in said casing mounted for oscillation about the axis of the latter, a spring support in said casing for said blade tending to bring the cutting edge of said blade into engagement with the inner cylindrical surface of said casing, the outer portion of the semi-'cylinder being cut away between the ends thereof along a plane extending substantially tangentially to the inner cylindrical surface thereof at a plurality of regions to provide a cutting edge at the intersection of said plane and the inner cylindrical surface, said semi-cylinder being further cut away to provide a plurality of slots extending from the cutting edge to receive hairs to be cut, and means for swinging the cutting edge of the movable blade to a distance not less than -35 millimeters from the stationary cutting edge.

6. A dry shaver comprising a cylindrical casing having a longitudinal slot, one side of which constitutes the cutting stationary edge, a bearing plane for the skin formed on the outer face of said casing being substantially tangential to the cylindrical inner surface of said casing along a hne coinciding with the cutting edge of said 1' simian@ and the zlirestsn of me@ CLI through he axis o blade and the staonsry c i6. A dry haver as clamea in claim 9, mmmcsing further means im" imparting tc said mov able blade au oscillang nmtion and s: plgte moines?, said dllvng means and adjustable cylinders against access mit hair.

ll. A. dry shaver comprising a cylindrical ses having a longitudinal slot, ons which @uiting edge of n of the beaing blade 'seing mts bram/'een b'ldges and a @cada mounted t@ u fs in said having its cutting "fige, a. heal ma outer face y tangential te :am casing along -1 @www edge a lade moimtec, to having its cutting ed gemelli; with said smb e spring;

cnnstiues the cutting statenary edge, a bearing; plane fo 53h@ skin formed en me omer face of said casing being sulfstantially tangential t@ the cylindrical inner surface of said easing along a line coinciding with the cutting edge of said statonary blade, the particu of the bearing sufzwe Upposte to the stationary blade being provided with a plurality of deep cuts wrmal to said blade, a, :ns1/able blade mounted to oscillas in said casing' and having its cutting edge in engafgw ment with said inner sylindrical surase, with .a cylindrical bearing surface foi supmrt ing said movable Made, augularly acusmble cylinders having eccent'fic holes umich pins are elastically sugported and a base zsLQgL-mwrti carrying said cylinders and said 035mg,

12. A dry 'shaver comprising a cylimlcal cas ing having e. narrow dscontnucauslnnglibudnal slot, one side of which constitulzes me smtonary blade, s plurality nf marras.' '.arfges tzm said slot, a bearing plane for the @sin imma@ an the eater face of said casing being subst sly tangential m the inner: cylmisal sm' @l said casing along a line coimlrsg with :21trtng edge of said stationary mafie, She ai? sg, El mzstmg edge wilma! Slat famed plans for @ne the healing surface opposite t@ vias s'mims'ay blade being provided with a, plursty si cuts batwen said briges and a movable blade mmmd for osllatlim said smi its cutting edge in engagement sai@ limer cylindrlca surface, plus with a -cyln rical nears i g surface for supporting movable; angularly adjustable cylinders having ssamm@ holes in which said plus are elastic-ally suppuef and a, base support cayng said cylinders mi Casin, l

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